Paul Romer’s research addresses one of the oldest questions in economics: What sustains economic growth in a physical world characterised by diminishing returns and scarcity? The answer: the rules societies establish to deal with advances in technology. He argues governments can increase the rate of growth - in ways that benefit all citizens - by creating systems of rules that encourage and respond to new technologies. The Stern School of Business' Urbanization Project, of which Romer is Director, addresses a truly historic challenge and opportunity: welcoming an additional 3 - 5 billion people to urban life in less than a century. The Project's first initiative helps existing cities plan for expansion. Its second initiative fosters the creation of entirely new cities because history shows that a new city offers a uniquely important opportunity to implement systemic social reform and speed up progress.